Why complex life could prove remarkably common in the universe

Do we live on a rare earth, so exceptional that it is pretty much alone in hosting a rich diversity of life, with almost all other planets being home to simple microbes at best? Or are we in a universe teeming with living things as complex as those here, meaning that we exist as part of a vast, cosmic zoo?

Debate on this rages on, but we say it’s time to accept that the latter is very likely.